Field of the Invention
The present invention generally relates to audio systems. More particularly, the present invention relates to the field of driving speakers in an audio system to produce sound.
Related Art
Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, audio devices, video equipment, and telephone systems have facilitated increased productivity and reduced costs in analyzing and communicating data in most areas of business, science, education and entertainment. Frequently, these advantageous results are realized through the use of audio systems that convey information via audio sounds. The type of audio system can have significant impacts on the performance and quality of the sound.
Audio systems usually include speakers for creating sound. Speakers typically create sound by vibrating a speaker cone (e.g., moving a speaker cone in and out) in accordance with inflections in an analog signal. Speakers are typically driven with an analog signal that corresponds to a sound waveform. Traditionally, the analog signal is applied to the terminals of the speaker which produce magnetic fields that push or pull the speaker cone to move in and out. The movement of the speaker cone displaces a volume of air producing sound waves. The amount of movement of the speaker cone and resulting air displacement is typically determined by the relative amplitude or voltage level of the analog signal. The analog signal voltage is usually amplified by an amplification component before the signal is forwarded to a speaker input.
Achieving high sound quality and fidelity in analog audio systems can be difficult. Even though some analog systems may involve pulse width modulation (e.g., Class D amplification) they typically require dedicated special-purpose hardware in addition to system logic components (e.g., a digital to analog converter). Components dedicated to special functions typically consume system resources (occupy precious board space) and add costs. Coordinating additional connections and interactions can also complicate design efforts. In addition, the analog circuits used in a traditional audio system can consume a significant amount of power.